Fixed Pros: Indirect Restorations/Crowns Flashcards
Briefly describe indirect restorations.
A restoration that needs to be fabricated extra-orally prior to placement intraorally. The restoration is constructed on an accurate model of the dental arches.
What are the materials you can use for indirect restorations?
- composite resin
- alloys and ceramics
- gold
What are the advantages of indirect restorations?
- No plastic phase/no need to pack and cure
- Fabricated under lab conditions/no need to work inside mouth
- Improved aesthetics e.g.: ceramics)
- Can more predictably manage advanced cases
What are the disadvantages of indirect restorations?
- More visits required (at least 2)
- Needs careful planning and skilled execution
What are the indications for indirect restorations?
- teeth vulnerable to further breakdown
- heavily restored teeth
- reorganise the occlusal scheme during rehab
- an option for fixed replacement of missing teeth
- extensively restored abutment for a Co/Cr RPD
- Aesthetic reasons
List the types of indirect restorations.
- Inlay
- Onlay
- 3/4 crown
- 7/8 crown
- full coverage crown
- bridge pontic
- veneer
- implant supported-crown and bridge
What is an inlay?
A dental restoration made outside of the tooth to conform to the prepared cavity, which is then luted into the tooth. Does not involve the cusps.
What materials can you use for an inlay?
CR, gold alloys, ceramics
What are the requirements for an inlay?
- rounded line and point angles
- NO UNDERCUTS
- prep floor is flat or concave
- slightly divergent axial walls
- 6 degrees of taper
- PM’s should have 1 intact marginal ridge, M’s may be MOD design
- for small to moderate-sized lesions
What is an onlay?
An indirect restoration that restores one+ cusps joined to occlusal surfaces or the entire O surface.
What are the advantages of onlays?
- provides cuspal protection after RCT
- less expensive than full coverage crowns
If you’re making an olay and using ceramics, what do you need to keep in mind?
- Ceramics are brittle. They need minimum 1.5mm thickness, which means the preparation needs to be more aggressive.
What are the materials you can use for onlays?
CR, ceramics, metal alloys
What are metal-ceramic combos used for in indirect restorations?
Crowns and fixed partial dentures.
What are the advantages of using metal ceramics?
- Very strong and durable
- Wear resistance is high
- the metal part of the material has high fracture resistance
What are the disadvantages of using metal-ceramic materials?
- Cavity prep is moderately aggressive
- Multiple appts required - Wear resistance is high but this may wear the opposing teeth
- ceramic fractures on impact
- there may be sensitivity to the base metal
- cost is higher
What are the advantages of using ceramics?
- good aesthetics
- is biocompatible and usually well-tolerated
- generally high wear resistance
What are the disadvantages of using ceramics?
- Is brittle and can fracture under heavy loads
- Multiple appts needed
- Wear resistance is high but may wear opposing teeth
- higher cost
What are the advantages of using cast-gold?
- high corrosion resistance
- least amount of TS removed
- high fracture and wear resistance
- is biocompatible; allergies rare
What are the disadvantages of using cast gold?
- aesthetics (not suited for anterior teeth)
